1. Field of the Invention
This invention relates to control of insects, particularly to the killing of coleopterous chewing pests using insecticide compositions comprising an attractant and a toxicant. Additionally, the invention relates to a process for the manufacture of the compositions using plastisol material.
2. Description of the Prior Art
Boll weevils, Anthonomus grandis Boheman (Coleoptera: Curculionidae), are insect pests that feed on cotton plants causing serious damage to the plants and reducing harvest yield. Previous attempts have been made to trap, kill or destroy the boll weevil, for example, male sex pheromone Grandlure baited traps have been used to capture the weevils that were attracted to it. Compositions alone or in combination with traps have incorporated the use of feeding stimulants to induce the insects to feed on a toxic bait. Traps were also made of paper or plastic in the form of a container attached to the top of a cone capturing weevils alive. U.S. Pat. No. 3,803,303 describes boll weevil attractant compositions using Grandlure. Additionally, U.S. Pat. No. 4,027,420 describes an apparatus and method for attracting and killing boll weevils in which a solid support is used to contain and attractant as well as a toxicant.
U.S. Pat. No. 3,803,303 describes polymeric compositions for attracting boll weevils using a sex attractant in combination with polyethylene glycol and a toxicant such as p-dichlorobenzene. Additionally the plant attractants, caryophylline oxide and beta-bisabalol were used. In each case the attractant was applied to cotton dental-rolls.
U.S. Pat. No. 4,027,420 describes an apparatus and method for attracting and killing boll weevils. The apparatus consists of two pieces of posterboard connected together. The posterboard is impregnated with an attractant and a toxicant.
There are many disadvantages in using presently available insecticides. Toxicity to humans and animals is high. Additionally, many of the compounds are not readily degradable and thus tend toward environmental pollution. It can be seen there is a pressing need to provide a means for reducing or eliminating the amount of toxic insecticides used in the management of insect pests.
The prior art uses of toxic baits have been in various water-based forms. These bait formulations have been subject to dissolution, dilution, or wash-off by rain. More specifically, there is a need for a means to kill chewing insect pests that does not suffer the disadvantages of the prior art insecticide traps or baits described above and that is species specific thus protecting the insect species that are beneficial to crop plants.